A conventional book binding device is disclosed in, for example, Patent Document 1. The book binding device disclosed in Patent Document 1 comprises a clamper reciprocally movable along a conveying path, a series of processing units (a milling unit, a glue application unit and a cover attachment unit) arranged along the conveying path, a cover supply unit supplying a cover to the cover attachment unit, and a control unit controlling these units and the clamper.
A guide rail and an endless drive chain are arranged above the series of processing units to extend along the conveying path and the clamper is slidably attached to the guide rail and fixed to the endless drive chain. The clamper has a pair of clamp plates, and a book block (a bundle of sheets or signatures for manufacturing a book) is gripped between the pair of clamp plates at a book block supply position which is disposed at one end of the conveying path while standing with a spine thereof downwardly facing.
The milling unit includes a milling cutter and a pair of guide plates. While the book block gripped between the pair of clamp plates passes over the milling cutter, a bottom part of the book block is inserted between the pair of guide plates, and the spine of the book block is milled while being supported by the guide plates at the bottom part thereof, whereby a pretreatment for uniform application of glue to the spine of the book block is performed.
The glue application unit includes a glue tank, glue application rollers applying glue to the spine of the book block, and a scrape roller wiping out extra glue of the book block. While the book block gripped between the pair of clamp plates passes over the glue tank, the glue is applied to the spine of the book block.
The cover attachment unit includes a bottom plate and a pair of nip plates arranged on the bottom plate. The cover supplying unit includes a shelf on which the covers are placed, and a cover conveying mechanism conveying the cover from the shelf onto the base plate and pair of nip plates. The cover conveying mechanism includes a pair of scoring roller pairs forming folds at predetermined positions on the cover.
After an operation of bookbinding starts, the cover is conveyed from the shelf onto the bottom plate and pair of nip plates by the cover conveying mechanism. During conveying the cover, parallel two folds are formed on the cover by the pair of scoring roller pairs. When the book block gripped between the pair of clamp plates arrives and stops at a predetermined position on the cover attachment unit, the bottom plate as well as the pair of nip plates raises to a nipping position, thereby the cover is pressed against the spine of the book block by the bottom plate, and then the spine of the book block are nipped between the pair of nip plates so that the cover is pressed against both sides of the spine of the book block so as to be attached to the book block, and a product is manufactured.
Thereafter the guide rail and endless drive chain raise and the product gripped by the pair of clamp plates is conveyed to the book block supply position and then the product is discharged by opening the pair of clamp plates.
In this book binding device, before start of operation of the book binding device, as parameters of the book binding device, the gap distance between the pair of clamp plates of the clamper at an open position thereof, the gap distance between the pair of guide plates of the milling unit, the gap distance between the pair of nip plates of the cover attachment unit at an open position thereof, and the gap distance between the pair of scoring rollers of the cover conveying mechanism are automatically calculated by the control unit based on the information about the thickness about a book block to be bound, and then initial settings of these parameters are performed according to the calculated values, whereby the production efficiency is improved.
In some conventional book binding devices, the height of a scrape roller as a parameter of a glue application unit is automatically preset based on the information about the thickness of a book block to be bound in order to apply glue to the book block at an appropriate thickness and improve a finish of book binding. Also, in some conventional book binding devices, the height of a bottom plate with a pair of nip plates as parameters of a cover attachment unit is automatically preset based on the information about the thickness of a book block to be bound in order to achieve cover attachment suitable for the thickness of glue applied to the book block and improve a finish of book binding (for example, Patent Documents 2 and 3).
However, even if book blocks have the same thickness, because a set of sheets or signatures making up the respective book blocks do not always have the same quality and thickness, the set values of the parameters automatically calculated based on the information about the thickness of a book block to be bound by the book binding device are not always appropriate. Consequently, when a book binding is performed using the set values of the parameters automatically calculated by the book binding device, the trouble such as partial wrinkles or breaks of a book block, a paper jam, and a defect of cover attachment sometimes arises, or the quality of a finishing of book binding sometimes deteriorates. Furthermore, because an appearance of a product is subjectively evaluated and a criteria of the evaluation varies for each of users, when a bookbinding is performed using the set values of the parameters automatically calculated by the book binding device, products suitable for tastes of the users cannot sometimes be obtained.
Therefore, in the prior art, after the information about the thickness of a book block to be bound is inputted to the book binding device and the set values of the parameters automatically calculated by the book binding device, these set values are adjusted by the user depending on kinds of book blocks and then an initial setting of the book binding device is performed according to the adjusted set values of the parameters so that products suitable for the user's taste are manufactured.
However, this adjustment work is troublesome and especially, this adjustment work is required for each lot in manufacturing of a wide variety of products in small quantities, whereby the manufacturing efficiency is substantially decreased.